A combined magnetophoresis/dielectrophoresis based microbead array as high-throughput biomolecular tweezers

Abstract

In this paper we describe a combined magnetophoresis (MAP) and dielectrophoresis (DEP) based platform for high throughput characterization of specifi c biomolecular interactions. The magnetic manipulation enables parallel loading of individual magnetic beads onto a magnetic pad array, while the combination of tightly controlled opposing magnetic and dielectrophoretic (DEP) forces is employed to produce characteristic out-of-plane (z-axial) bead displacement. We optimized design parameters to evenly load 2.8 µm biomolecule functionalized paramagnetic beads onto magnetic pads, and demonstrate the ability of our tweezers to discriminate between specifi c antibody-antigen bond from non-specifi c bond formed between bead and pad surface.